Stellar Explosion Seen in 3-D

by SPACE.com Staff | August 04, 2010 11:32am ET

This artist’s concept show the material around a recently exploded star, known as Supernova 1987A, is based on observations which have revealed a three dimensional view of the distribution of the expelled material. The original blast was not only powerful, it was also more concentrated in one particular direction. This image shows the different elements present in SN 1987A: two outer rings, one inner ring and the deformed, innermost expelled material.Credit: ESO/ L. Calçada

Astronomers have generated a 3-D view at a famed
exploding star to reveal how fast the powerful supernova ejected material when
it died.

The stunning view comes from new observations of the
well-known Supernova 1987A, which as its name suggests exploded in 1987 and was
the first naked-eye star explosion seen in 383 years. [Illustration of the 3-D
supernova.]

The original blast was not only powerful, it was also
more concentrated in one particular direction, according to the new study. This
is a strong indication that the supernova must have been very turbulent,
supporting the most recent computer models, researchers said.

"We have established the velocity distribution of
the inner ejecta of Supernova
1987A," said the study's lead author Karina Kjaer,
an astronomer with the European Southern Observatory. "Just how a supernova
explodes is not very well understood, but the way the star
exploded is imprinted on this inner material. We can see that this material was
not ejected symmetrically in all directions, but rather seems to have had a
preferred direction. Besides, this direction is different to what was expected
from the position of the ring."

The researchers found that the first material ejected from the supernova travelled at a whopping 62
million mph (100 million kph). That is nearly one-tenth of the speed of
light or around 100,000 times faster than a passenger jet, researchers said. Even
at this breakneck speed, the material took 10 years to reach a previously
existing ring of gas and dust puffed out from the dying star, they added.

The new observations also showed that another
wave of material is travelling 10 times more slowly and is being heated by
radioactive elements created in the explosion.

Such asymmetric behavior
was predicted by some of the most recent computer models of supernovae, which
found that large-scale instabilities take place during the explosion. The new
observations provide the first direct confirmation of such models.

Supernovas are the spectacular finale for massive stars
that, once arriving at the end of their life, detonate to expel vast quantities
of material. Such stars are larger than our sun, which will end its days in a
more subdued manner.

Supernova 1987A, however, is one such star explosion and
is located in the nearby Large Magellanic Cloud, a satellite galaxy of our own
Milky Way. Because of its relative closeness, the supernova has made it
possible for astronomers to study the explosion
of a massive star and its aftermath in more detail than ever
before.

Kjaer and her colleagues used ESO's Very Large Telescope in Chile to measure the
speed at which Supernova 1987A flung material outward.

The research will be detailed in the journal Astronomy
and Astrophysics.